Videotex systems interactively connect a host computer to large groups of geographically widely-distributed terminals. In this manner, remotely located information can be retrieved by the terminals.
In order to establish communication paths between the terminals and the host computer, telephone connections have been employed. While such telephone communications have become popular in videotex systems, the subscribers to such a system, must not only pay the charges for the videotex system, but also the telephone charges. The telephone charges can become very substantial as compared to the videotex service charges.
The telephone charges are prohibitively large, especially where the terminal is located at a great distance from the host computer. Thus, it would be highly desirable to have a new and improved method and apparatus for an information retrieval system, such as a videotex system, to enable the terminals to communicate relatively inexpensively with a remotely located host computer over communication paths, such as telephone lines. Such a technique should reduce the service charges, as compared to conventional techniques.
Moreover, in such a system where information is retrieved from distant locations, it is desirable to enable complete computer programs to be exercised locally by the user interacting with a terminal in an economical and efficient manner. In this regard, if a program requires a great deal of real time to execute, the cost of maintaining the communication path during the execution thereof, may be substantial, and in some instances, prohibitively high. Thus, a more cost effective and efficient system for enabling the execution of longer programs, would be highly desirable.